It is becoming a cautionary tale of two countries, their myths and instinctive reactions. One, a great superpower, reveres but also distrusts power itself. The over-arching state is a source of suspicion. Citizens naturally fear it; they balk at policies that seem to hand over influence to a distant, federal centre. They see themselves as vibrant individuals, sons of the pioneers. Popular culture lauds Jason Bourne, a lonely warrior against malignant, controlling spooks. The great heroes of journalism revealed presidential conspiracies. Today's most manifest foes are giant government schemes in the style of "Obamacare", a supposed bewilderment of tick boxes, crocked computers and cash leaking from a denuded exchequer. Reforms of this type may be ritually denounced as "socialism", taking away the hallowed right of ordinary Joes to spend 15% of their income on pills and visits to a doctor who earns considerably more than Joe.

The other nation – once the centre of an empire that spanned the world – may boast of its closeness to this introverted superpower. It believes it has a special relationship, speaks the same language, shares aspirations and secrets. But the difference at the core is profound. Britain still trusts in the benevolent state. Safeguarding its National Health Service, a Labour creation that dwarfs Obama's reform, is the most totemic policy in its politics, a "national religion". Voters still hanker after a return to state-run water, gas, electricity and rail services when they talk to pollsters. James Bond, a laughing, fornicating cavalier of a secret agent, is the spook of choice. Editors across Fleet Street denounce unpatriotic journalists who rock M's boat. The British assume governments are on their side. They may not hold much personal brief for the politicians or the mandarins who serve them. But they still look to Whitehall and Westminster for help, for action, for everything. And it is this distinction, this canyon of incomprehension, which so shapes the world of the US National Security Agency and its faithful servant, GCHQ Cheltenham.

There is a simple, media-friendly narrative that seems to encompass six months of revelations from Edward Snowden. It finds American editors and politicians swiftly incensed by the stories in the Guardian, New York Times, Washington Post and Der Spiegel. Complacent reassurances from security chiefs don't wash. Courts belabour "Orwellian" practices. President Obama sets up a high-level review group to tell him what needs to be done. These experienced DC trusties, reporting last week, recommend fundamental shifts and reforms in NSA behaviour: on encryption, on the storage of meta data, on surveillance of overseas leaders, and much, much more.

Meanwhile the Snowden trove, carefully decoded, its contents weighed, continues to surprise and shock. What's GCHQ doing bugging German government offices, listening to EU Commission conversations, tuning in to hear what the Israeli PM's got to say … or leering over Unicef's shoulder, for heaven's sake? Are our enemies in the supposed war on terror doctors saving lives in the African bush? This story, self-evidently, isn't over. Whistles will blow, and blow again. The spooks of high technology will have much more to answer for in the coming year.

Cross the Atlantic, though: compare and contrast. GCHQ, asked to comment, says no comment. The men in expensive suits who head MI5, MI6 and Cheltenham field patsy questions from a parliamentary committee and talk the plangent generalities of harm done. The editor of the Guardian finds himself under sustained attack, computer discs destroyed, Scotland Yard squads duly deployed, MPs summoning him to defend this or that. We can, and should, find such a simple narrative distressing. American democracy awakes and reacts. British democracy sleeps, and shoots messengers. The New York Times clears the front page. The London Times fits in something at the bottom of page 10. The Daily Mail exercises its sacred right to ignore.

But, of course, no narrative involving so much encryption can be that simple. This is a saga of many connected strands. One, last week, brought us Sir Peter Gibson's part-completed report on rendition and proof positive – in words the Mail did print – of "the bleak truth that Britain … was complicit in torture". Our spies sat idly by and watched suspects treated "with extreme hardship". And our top spies formally assured ministers and the monxitors of the intelligence and security committee that British hands were clean. It was a lie; one lie among many. Yet the same ISC is now lined up to finish off Gibson's inquiry (when, that is, it has stopped fawning over M and the rest of the security alphabet as well as performing the review role Obama gave to a hand-picked, superbly resourced team).

But where does dissembling stop? And where does true reform begin? Often it is the reforms themselves that bring bigger trouble. America failed to prevent the horrors of 9/11 because it had so many agencies tripping over each other and not communicating. Reform meant that Snowden, a humble contractor, along with hundreds of thousands more, had top-level access to everything we now see swilling forth. Secrecy guarded by sharing everything? Good intentions undermined by bureaucratic blindness? Intelligence commissioned from Cheltenham poured into an American bucket with a hole in the bottom.

There are no simple truths here, merely a tangle of complexities. The saintly scions of the "intelligence community" who "keep us safe from harm" were putting their names to dodgy Iraq dossiers a decade ago. Espionage is a fallible business, human at the point of analysis and decision-making. Of course, politicians put on kid gloves when they reach for the files. Who wants to disregard an awful warning that could come back to haunt them? Better go quietly along with the herd, better not scare the horses.

But here the two worlds of DC and Cheltenham intersect at last. There is no absolute security, just as there are no definitive reforms. There is always desperate peril to secrecy. Horrible things happen when nobody knows. Exaggeration – about everything from terrorist threats to budget cuts – is endemic behind closed doors. Perhaps America, in the decade after 9/11, has feared and promised too much. But certainly Britain, drifting in a haze of conspiratorial chappishness, has changed far too little. The answer to both ailments is out there for us all to register. It is what we expect, what we understand and demand, that matters most. This secret world is our world, too. Democracy's real responses begin on the streets where we live, where we wake up, calculate the risks, and insist on having our say.